Published byStanford Medicine

Nearly 60 percent of American adults turn to the Internet in search of health information. Now investigators at Stanford and Microsoft Research have joined forces to develop a method for mining consumers’ web search history and identifying unreported side effects of drugs or drug combinations.

For the study, the Microsoft researchers developed automated tools that were used to analyze anonymized data from 82 million drug, symptom and condition searches performed by 6 million Internet users who consented to sharing their search history for research purposes. As my colleague explains in a release:

… [T]he team used the automated tools to identify searches for information on paroxetine, pravastatin or both during 2010. The tools then computed the likelihood that users in each group would also search for hyperglycemia – or almost 80 of its symptoms or descriptors, such as “high blood sugar,” “blurry vision,” “frequent urination” or “dehydration.”

…

Among people who searched for the drug paroxetine or its brand names in 2010, about 5 percent also searched for one of the hyperglycemia-related terms. For pravastatin and its brand names, the rate was below 4 percent. But for those who searched for both drugs, suggesting that they might be taking both drugs, the search rate for hyperglycemia was 10 percent.

To test the accuracy of the search engine analysis, the team looked at 31 drug-drug interactions already known to cause hyperglycemia, and 31 interactions known to be safe. Overall, the drugs with known interactions led to more search queries on hyperglycemia. But the results also suggested that around 12 percent of users searching for drug combinations known to have no interactions also had an unusually high rate of hyperglycemia searches, which would lead researchers down dead ends if they pursued them.

Stanford professor and study co-author Russ Altman, MD, PhD, commented on the findings saying, “I believe patients are telling us lots of things about drugs, and we need to figure out ways to listen… This is just one way of listening and one application.”

A New York Times story published today noted that researchers are “also now thinking about how to add new sources of information, like behavioral data and information from social media sources.”